In multi-projector systems, a casually-arranged set of projectors will produce a composite display having an irregular outline due to geometric distortions caused by misalignment of the projectors, keystoning, and the like. These artifacts can be corrected by calibrating the system using a camera. This is true both for tiled displays, where the objective is to create a large display by minimizing projection overlap, as well as for super-bright displays, where the objective is to maximize projection overlap to maximize the brightness of the display. The same is true for single-projector systems.
It is desirable that the composite display have a smooth rectangular shape. It is also desirable to maximize the size of this rectangle, both for multi-projector and single-projector systems. What is needed is a display mask in the form of the largest rectangle that fits within the projection of the system.